There is method behind the media devised 'madness' of Donald Trump. Don't trust polls, which are rigged, both by composition and the framing of qestions. Trump is as popular now as he was when elected.
The Russia Probe and Special Prosecuter Mueller have come up with nothing and have become increasingly desperate and threatening to potential witnesses, including raiding the home of Paul Manafort. They've tried to broaden the scope of the investigation to 'financial' irregularities since the original parameters have turned up nothing incriminating, just innuendo. Their problem is there is nothing there.
As long Trump does not sell out the creepy NeoCons in his own party (like Sens. Graham , McCain, Gov. Kasich and assoc.), or the globalist NeoLibs of the Dems he'll do fine. He's got another 7.5 years to make American great again, because his opponents have nothing but a smear campaign to offer as an alternative to the utterly failed programs of global free market capitalism and cultural abasement.
He needs to double down on what got him elected. That starts with economic nationalism, rebuilding an integrated, national, industrial economy (with steel and textile mills) and its transportation infrastructure. The ONLY way to do that is with Tariffs. He has to renationalize the US Greenback by reestablishing sovereign national control of the currency by ditching monetarism (free trade in currency and credit).
He's got to get the US out of the business of regime change, and imposing US style democracy on the rest of the world. It's never worked and has brought with it catastrophic blow back.
He's had some notable successes by putting Neil Gorsuch on the Supreme Court, and removing the US from the phony boondoggle of the Paris Accord. But the tough sledding is still to come in taking on the American Free Trade Economic Establishment. If he keeps people like Steve Bannon with a clear vision of a national policy as his key advisors, he'll do fine.